Electrical code wants a conductive ground. Things that make a better conductor include moisture, finer soils, and more surface area on the electrode, and a wider area of earth included in that electrode 'system'. For example, code requires rods to be separated by six feet so that the surface area of one rod does not 'connect' to the same earth used by the surface of another.
Earthing for surges involves both conductivity and equipotential. An example of equipotenial. Lightning strikes a tree. Therefore a nearby cow is electrocuted. Why? Cow is earthed by separated fore and hind legs. Therefore the connection from cloud to earthborn charges is through sky, through tree, into earth, up cow's hind legs, down fore legs, and then through earth to those earthborne charges.
How to protect the cow? Convert earth beneath that cow into a single point ground. Create equipotential. Surround the cow with a buried loop so that earth beneath the cow is equipotential. Charges that would have passed through the cow, instead, encircle the cow on that buried loop. Now all earth beneath the cow is equipotential - cow is unharmed.
Even though voltage beneath a cow might rise by thousands of volts, no incoming and outgoing path exists. Therefore no surge current exists. Therefore no harm.
People want to think of surge protection in terms of a magic box. The protector is not protection. The protector is only as effective as its earth ground. Therefore your telco (connected to overhead wires all over town) suffers typically 100 surges during every thunderstorm
- and no damage. Why? Telcos routinely use Ufer grounds or something equivalent to create even better equipotential.
We can never make the building sufficiently equipotential. So earthing must be more conductive. But we can never make those electrodes sufficiently conductive. So we also make better equipotenial.
Having said this, more conductive electrodes that exceed 1990 Code will be sufficient for most homes. However if we built homes standard with Ufer grounds, a buried loop outside the foundation, or even integrate basement floor concrete rebar into the earthing system, then significantly improved earthing makes a minor increase in protection. That minor increase is essential for any facility that can never ever suffer surge damage.
Again, protection is about electrodes that are more conductive and that provide equipotential.
Surge protection also is about a connection as short as possible because wire is just not sufficently conductive. Whereas fifty feet of wire from breaker box to an electrical receptacle is less than 0.2 ohms resistance; that same wire may be 120 ohms impedance to a surge. Impedance is little changed by increasing wire diameter and mostly decreased by making that wire shorter. Home earthing is typically less than 10 feet. Sharp bends, bundled with other wires, or ground wire inside a metallic conduit will also increase impedance - reduce conductivity.
Polyphaser, an industry benchmark (the niave never heard of Polyphaser and foolishly believe APC, Belkin, or Monster Cable are good), makes a protector that has no earthing connection. Instead, that protector mounts ON earth ground: zero foot earthing connection.
A ground wire up over the foundation and down to electrodes may be adjacent to other non-ground wires, have sharp bends, and too long. Better is to connect that ground wire through foundation and down to earth. Shorter distance. Few or no sharp bends. Separated from other wires. This also makes superior surge protection.
Some examples and suggestions to better understand the difference between earthing for human safety (the Code) and earthing for surge protection. That earthing electrode serves multiple purposes. Code is mostly concerned with human safety. But earthing is best also upgreaded for surge protection - transistor safety.